Toyota COMPUTER-CONTROLLED SYSTEM Training Manual page 166

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TROUBLESHOOTING - Symptom Chart
POSSIBLE CAUS E
SYMPTOM
SYSTEM COMPONENT PART TYPE OF TROUBLE
Fuel pump Drop in flow volum e
Injectors Drop in injection volum e
Fuel s stem y
Pressure regulator Fuel pressure too low
Insufficient
Fuel filter, fuel line Clogged
Poor drivability
power
Ignition system Spark plugs Misfir e
Manifold pressure
Electronic control
sensor (vacuum sensor) Voltage or resistanc e
system
Water temp. sensor
are incorrect
Thro
tt
le position sensor
PSW signal not outpu t
Circuit opening relay FC circuit won't go o n
Fuel system
Injectors
Leaking, won't inject ,
Engine stalls injects continuousl y
sho
rt
ly after
sta
rt
ing
Cold sta
rt
injector
Leakage, inject s
Cold sta
rt
system
continuousl y
Sta
rt
injector time SW
Stays on continuousl y
Engine stalls
Manifold pressure
when accele-
Electronic control
sensor (vacuum sensor)
Voltage or resistanc e
rator pedal is
system
are incorrect
Engine stalling
depressed
Water temp . senso r
Thro
tt
le position sensor
Malfunctionin g
Air induction s ste m
Engine stalls
y
when accele-
Air valve Stays closed
rator pedal is
Electronic control Manifold pressure Voltage or resistanc e
released
system sensor (vacuum sensor) are incorrect
Engine stalls Air induction system ISC valve Malfunctionin g
when ai r
conditioner i s
switched on
Electronic control
Air conditioner switch Signal not outpu t
syste m
Engine stalls
Air induction system ISC valve Malfunctionin g
when ATM i s
shifted fro m
"N" to "D"
Electronic control
Neutral sta
rt
switch
Signal not outpu t
position
syste m
158